Micro-homogenizing apparatus



Nov. 26, 1963 c. J. Fu.z l

MICRO-HOMOGENIZING APPARATUS 5 Sheets-Sheet l Filed April 13, 1961 o R(244/9255 rf /7 Z BY B2.; ATTO R N EY Nov. 26, 1963 c. J. FlLzMICRO-HoMoGENIzING APPARATUS Nov. 26, 1963 c. J. FlLz MICRO-HOMOGENIZINGAPPARATUS 3 Sheets-Sheet 3 Filed April 13, 1961 WQ v iNvENToR (2u/P455 JF/z d? United States Patent O 3,112,081 MICRO-HOMOGENIZING APPARATUSCharles J. Filz, Weston, Conn., assignor to Ivan Sorvall, Inc., Norwalk,Conn., a corporation of New York Filed Apr. 13, 1961, Ser. No. 102,76623 Claims. (Cl. 241-285) This invention relates to macerating apparatusand more particularly to apparatus for homogenizing or comminuting'biological and physiological specimens in small volume quantities inthe order of 0.5 milliliter to 5.0 milliliters.

In biological study and analysis it is often necessary to macerate orcomminute biological materials to a tine homogeneous state, and wherethe specimens are comparatively small in volume, it is desirable toprovide suitable apparatus capable of performing this work.

The present invention comprises an apparatus driven by a high speedmotor which, by way of a speed multiplying device, rotates a cuttingknife within a small container in which the specimen is placed. Since itis often necessary to avoid contaminating the specimen, it is desirableto perform the macerating or homogenizing action in a small cell orcontainer which is capable of being properly isolated from the drivemechanism as well as from the ambient atmosphere, before, during andafter the time the macerating action takes place. Accordingly, a salientfeature of the present invention is Ithe provision of a sealingarrangement for the chamber which effectively protects the specimen asit is being processed therein. Furthermore, the sealed chamber assemblyis constructed in such a manner as to provide a quick releasableattachment means by which the sealed container including the maceratingor homogenizing knife is readily connected to or disconnected from thedrive mechanism of the apparatus whereby the use `of special tools isobviated.

Furthermore, -a novel arrangement of a spring loaded seal diaphragm anda cooperating seal washer is provided for maintaining the integrity ofthe seal for the specimen chamber and rotor shaft assembly before thelatter is connected to the drive assembly, during the homogenizingprocess and after the chamber assembly is removed from the driveassembly. Other improved mechanical structures and arrangements areprovided for facilitating the quick and easy assembly and disassembly ofthe various parts of the apparatus.

Still other objects and advantages of the invention will be apparentfrom the specification.

The features of novelty which are believed to be characteristic of theinvention are set forth herein and will best be understood, both as totheir fundamental principles and as to their particular embodiments, byreference to the specification and accompanying drawings, in which:

FIGURE l is a vertical elevational view of the apparatus of the presentinvention, some parts being in outline form;

FIG. 2 is a greatly enlarged, vertical central cross section of aportion of the apparatus shown in FIG. l, shown partly in elevation, andsome parts being omitted;

FIG. 3 is an elevation View of a fragmentary portion of the apparatusshown in FIG. 2, showing two positions of the locking mechanism for thespecimen container;

FIG. 4 is a view taken on line 4-4 of FIG. 3;

FIG. 5 is a greatly enlarged exploded view, partly in section and partlyin elevation showing the specimen container and the connect anddisconnect elements while said parts are separated;

FIG. 6 is a fragmentary view of a portion of the elements shown in FIG.5, showing the parts in the connected position;

FIG. 7 is a view taken on line 7-7 of FIG. 6;

ICC

FIG. 8 is a very greatly enlarged elevation view of a diaphragm sealspring core;

FIG. 9 is an edge View of the spring core shown in FIG. 8; and

FIG. 10 is an alternative embodiment of a specimen cup utilized in theapparatus herein.

Referring now to the drawings in detail, and particularly to FIGS. l and2, there is shown an electric motor 21 which is mounted on a bracket 22that -is connected to a suitable stand or platform, not shown. Connectedto the bottom of motor 21 is a shaft housing 23 which contains a driveshaft, not shown. Threadably connected into shaft housing 23 is a driveassembly body 24 made of an aluminum casting or the like, said bodyhaving an upwardly extending stub 26 threadably inserted into the lowerend of shaft housing 23. Stub 26 and drive assembly body 24 are securedfirmly to shaft housing .23 by means of a stainless steel lock nut 27that threadably surrounds stub 26.

Stub 26 has a vertical aperture 28 which extends through the upperportion of body Z4, the lower portion of which also has an aperture 29axially aligned with aperture 28. Positioned securely in apertures 28and 2'9 are ball bearings 31 and 32, respectively, within which isrotatably mounted drive spindle 33, of stainless steel. Connected to theupper end of drive spindle 33 by means of set screw 34 is a circularrotor shaft collar 35, the upper portion of which has a recess whichaccommodates by force fit a circular collar insert 36. Collar insert -36has a circular interior surface which is fluted, and which mates withthe lower yiiuted end of the drive shaft, not shown, in shaft housing 23whereby the rotation of said drive shaft by motor 21 causes the rotationof drive spindle 33.

rive assembly body has a large horizontal recess 37 in the areaintermediate the ends of drive spindle 33. Freely rotatable within saidrecess is drive pulley 38 made of aluminum or the like, and connected tosaid spindle by `means of a pair of set screws 39 extending through anupwardly extending axial stub 41 on said pulley. Interposed between thebottom surface of `drive pulley 38 and bearing 32 is a spacer bushing4-2 of aluminum which serves to fix the axial location of drive pulley38 and spindle 33 in respect of bearing 32 and snap ring 44 upon whichsaid bearing rests.

Another portion of drive assembly body 24 has a pair of axially alignedvertical apertures `45 and 46 which are separated by a horizontal recess47. Mounted in apertures 45 and 46 is a pair of spaced apart bearings 48and 49, respectively. Rotatably supported by bearings 48 and 49 isa highspeed spindle 51. Vertical aperture y45 is covered by a bearing cap 52which not only prevents external dirt from entering the apparatus butalso provides access to the operating parts for cleaning or replacementpurposes.

Mounted on high speed spindle 51 within recess 47 is a high speed slavepulley 53 of aluminum which has an upwardly extending stub 54 throughwhich a pair of set screws 56 extend for secu-ring said pulley to saidspindle. The peripheral surfaces of both drive pulley 38 and high speedslave pulley 53 are serrated in the form of evenly distributed laterallyarrayed 4teeth 57 and 58, respectively, Iwhich are engaged by a timingbelt 59 made of rubber, or .the like, the interior surface of saidtiming belt having a plurality of serrations or teeth rfor engaging theteeth on said pulleys. The rotation of the larger diameter pulley 38produces the higher speed rotation of the smaller diameter slave pulley53 whereby spindle 51 is rotated at a considerably higher speed thanthat of drive spindle 33.

The Working elements within drive assembly body 24 are protected bymeans of a suitably formed rguard 68 made of sheet metal, such asaluminum, Steel or the like,

said guard enclosing all of the open parts of said drive assembly bodyand being secured thereto by means of a pair of screw bolts 61. A slot`62 (lFIG. 2) is provided between an edge of guard 60 and body 24 topermit air `to circulate into the interior of the guard to cool thedrive elements composed of pulleys 38 and 53, and drive belt S9.Vibration of said guard `61 is prevented or minimized by the dampingeffect of isolation bushings 63 mounted between said guard and body 24and maintained in position by washers 64 secured by the heads of bolts62.

Drive assembly body 24 has a downwardly extending stub 66 whose centralvertical aperture 67 is coaxial with aperture 46, and through which thelower portion of high speed spindle 51 extends.

Inserted into aperture 67 is a circular seal housing adapter 68 ofstainless steel, the peripheral surface of which has an annular recess71 accommodating an O-ring 72 of rubber, neoprene, or the like, whichserves to hold said adapter 68 in place. The lower end of adapter 68 hasan annular outwardly extending ange 73 (FIGS. 5 and 6) which extendsover the lower edge of stub 66. The central bore of adapter 68 isthreaded for the purpose of accommodating a suitable threaded tool tofacilitate its removal, for example, when necessary to change thebearings or for cleaning the apparatus.

Mounted on the exterior of stub 66 is a pair of downwardly extendingdetent springs 76, made of spring tempered stainless steel andpositioned diametrically opposite one another (FIGS. l, 3, 5, 6), eachhaving at its lower end a V-shaped detent 77, the apex of which isdirected inwardly toward the axial center line of stub 66. Only theupper portions of springs 76 are secured to stub 66 by means of pains ofscrews 78 and 79, while their lower ends extend freely below stub 66 andare capable of ilexing laterally relative thereto.

Straddling detent springs 76 is a bowed or semi-circular locking clamp81, of stainless steel or the like, at the ends of which are integrallyformed perpendicular arms 82, the ends of which are pivotally connectedby means of shoulder screw 79 to stub 66. Arms 82 form elbows 83 withlocking clamp 81, said elbows having inwardly projecting bosses 84(tFIG. 5), which, when said clamp 81 is in locking position (FIGS. 2 and3), urge the free portions of detent springs 76 inwardly against therespective sides of stubs `66 and retain them in position. When clamp 81is in the raised or -unlocking position as in FIGS. l and 5, detentsprings 76 are free to ex outwardly -as indicated by the arrows in FIG.5.

Removably connectible to stub 66 is a specimen chamber, rotor shaft andseal assembly, generally designated 91 (FIGS. l, 2, 5, 6) whichcomprises a specimen chamber cup 92 made of seamless stainless steel andhaving a. plurality of inwardly extending, spaced apart, verticalflutings 93 formed integrally in its walls. Cup 92 is threadablyinsertable into a circular seal housing element 94 made of stainlesssteel, said element having an integral inwardly extending circularshoulder ring 96 surrounding a central aperture 97. The bottom of ring96 has an annular recess Iwhich partially accommodates a resilient sealring 98 of rectangular cross-section, made of rubber, neoprene or thelike, which serves to provide a liquid-tight seal between the top of cup92 and housing element 94. Seal housing element 94 has an upwardlyextending integral circular collar 99 within which its positioned acircular seal diaphragm, generally designated 101.

Seal diaphragm 101 constitutes a wafer-thin Phosphor bronze circularspring core 102 in the form of a web-like element having an outer pairof arcuate circularly arrayed slots 103 and an inner pair of arcuatecircularly arrayed slots 104, the latter pair of slots being concentricwith the former pair `(IFIG. 8). Slots 103 and 104 divide core 102 intothree concentric rings 10S, .105a and 105b. Rings 105 and 105a areconnected integrally by a pair of diametrically opposed bridges 106,while rings :1 and 105b are connected integrally by a pair ofdiametrically opposed bridges 107, said pairs of bridges being arrayedperpendicularly relative to each other. A resilient spring action isobtained when the inner portion of core 102 or ring 10511 is moved inthe direction of the perpendicular axis of said core. Normally, inrepose, core 102 assumes a at condition as shown in FIG. 9.

Outer ring 10S has a plurality of integrally formed spaced apart teeth`108 which are alternately bent in opposite directions perpendicular tothe plane of core 102, as shown in FIG. 9. Secured firmly to the centralaperture of ring 105 of core 102 is a stainless steel bushing 109. (FIG.5). All of core 102 and a portion of bushing 109 are embedded in ailexible coating or overlay 111 of silicone rubber, or the like, theperipheral area of said overlay enclosing .teeth 108 and being formed ina ring 112 of increased thickness 'and having an H-shaped cross-section(FIGS. 5 and 6), the upper surface of which extends somewhat above theupper edge of collar 99. Seal housing 94 is threadably insertable intotop cap 113, ring 112 forming a resilient means for providing an airandliquid-tight seal between seal housing 94 and top cap 113.

It will be noted that the H-shaped arrangement of ring 112 provides topand bottom pairs of concentric, circular, resilient, spaced apart ringswhich serve as respective double resilient members between seal housing94 and top cap 113 to enhance the integrity of the liquidand air-tightclosure. By embedding the Phosphor bronze core in a flexible plasticoverlay or coating 111, such as silicone rubber or other suitable inertresilient material, the spring function of the core is maintained whileat the same time the metallic material is protected from corrosion andreciprocal contamination with the contents of the specimen cup 92.

Cap 113 has an inwardly extending flange l114 which has a centralaperture 115 through which the upper stub 117 of elongated stainlesssteel rotor shaft 118 extends for free rotation of `the latter. Adjacentthe lower end of stub 117, rotor shaft 118 has an outwardly extendingintegral annular shoulder 119, a portion of the top surface of which isnormally urged lightly against the bottom surface of flange 114.

Shoulder 119 has a circular integral shelf 120 of reduced diameterbeneath which is mounted around rotor 118 a seal washer 121 made ofglass lled Teflon or the like, the upper surface of which forms asliding bearing with the bottom surface of shelf 120.

Although seal washer `121 may be made of any suitable low frictionmaterial, the substance known as Tellon provides a substantiallyfrictionless Surface which forms an excellent sliding bearing with thelower surface of shelf as the latter rotates with the rotation of rotorshaft 118. At the same time, the sliding mating surfaces of seal washer1211 and shelf 120 serve to form an effective seal therebetween in orderto maintain the integrity of the closure for the contents of specimencup 92.

Positioned coaxially within bushing 109 is a seal face ring 122 whoseinterior bore is spaced apart from the periphery of rotor shaft 118.Formed integrally at the upper end of ring 122 is an outwardly extendingllange 123, the top surface of which bears against the bottom surface ofseal washer 121. The bottom surface of flange 123 may rest upon theupper surface of overlay 111 of seal diaphragm 101, but in `someembodiments, said overlay may be provided with a circular recess intowhich said flange is nested snugly as shown in FIGS. 5 and 6, forexample. The outer periphery of ring [122 also lits snugly with theinterior surface of bushing 109. Thus, by means of the close fitting ofcomponents 109, 122, 123, 121 and 120, a sealed closure is provided forspecimen cup 92.

Threadably connected to the lower end of rotor shaft 113 is a microblade126 having a suitable shape and cutting edges, not shown, for properlymacerating or homogenizing the specimen material in cup 92 when saidshaft rotates freely within aperture 97 and the bore of ring 122.

When a biological or other Itype of specimen or material is to bemacerated or homogenized, it is first introduced into the open cup `92after which rotor shaft 118 surrounded by seal housing 94, seal washer121, sem face ring V122, and spring diaphragm 101, is inserted into saidcup which is then threadably secured to seal housing 94. Thereafter, topcap 113 is threadably secured to seal housing 94 to form a spill-proofspecimen chamber. Under the biasing action of seal diaphragm 101, flange114 is caused to bear lightly against shoulder 119 whereby shelf 129 isurged into contact with seal washer 121 as shown in FIG. 5, where saiddiaphragm is slightly bowed. Seal diaphragm 101 operates also tomaintain rotor shaft 11S in properly centered position relative to thechamber assembly before the latter is coupled to the drive assembly,during the homogeniz-ing process and .after it is uncoupled from thedrive assembly.

As is evident in the illustration of FIG. 5, the specimen chamberassembly 911 provides the facility for introducing the specimen to bemacerated into cup 92 and enclosing it, together with the maceratingblade 126, within a chamber which remains sealed while it is connectedto and removed from the drive apparatus. When the specimen chamber androtor -assembly is to be connected to the drive apparatus, no specialtools are required. The assembly is merely lifted by one hand intoposition where stub 117 ofl rotor shaft 118 enters into an elongatedcentral aperture 127 in the lower end of high speed spindle 51. Stub 117has a precision dowel pin 128 extending diametrically therethrough(FIGS. 5, 6, 7), the opposite end portions of which are snuglyaccommodated by corresponding longitudinal diametrically opposed slots129 in the end of high speed spindle 51 whereby rotation of the latterproduces the rotation of rotor shaft 118. In order to facilitate theentry of the ends of dowel pin 128 into slots 129 when the former is notaligned with the latter, the lower end of high speed spindle 51 has adouble bevel generated at surfaces 131, inclined at approximately ateach side of each slot 129 whereby pin 128 is slidably guided into slots129' should pin 12S not enter said slots directly. Rotor shaft 118rotates freely to the extent necessary within the specimen chamberassembly for permitting said pin to enter said slots as said assembly-is moved upwardly for the coupling operation.

The top surface of cap 113 has a circular counterbore 132. When thespecimen cup assembly is lifted upwardly for coupling to the driveassembly, counterbore 132 accommodates ange 73 with a snug fit (FIGS. 5,6). When stub @117 of rotor shaft 118 is coupled with high speed spindle51, V-shaped detents 77 move into an annular V-shaped recess 133 in theperipheral surface of top cap 113. As locking clamp 811 is moveddownwardly by the operator to cause bosses 84 to secure springs 76against outward movement, detents 77 pull the specimen cup assemblyupwardly against the bottom face of ange 73 `of the seal housing adapterv68. lIt will be noted that the pulling action of detents 77 isaccomplished by the upper portion thereof mating with the upper portionof recess 133, as illustrated in FIG. 6.

High speed spindle 51 has a predetermined length in relation to thebottom face of flange 73. During the procedure of coupling the specimencup assembly to the drive assembly, the lower end of spindle 51 extendsthrough aperture 115 of flange 114 and bears downwardly upon shoulder119 of rotor shaft 118 to the extent of between about 0.005" and 0.010"so that the top of shoulder 119 becomes spaced apart from flange 114.

By this action shoulder 119, and accordingly, rotor shaft- 118, aregiven freedom to rotate with the rotation of spindle 51 withouthindrance from flange 114. At the same time, the downward pressureproduced by the action of spindle 51 continues to urge shelf 120 againstseal washer 121 which, in turn, is urged against seal face ring 122 topreserve the seal for the specimen cup assembly while the lower surfaceof shelf rotates slidably against the upper surface of seal washer 121.In the operating position for macerating or homogenizing the contents ofcup 92, as shown in FIG. 6, seal diaphragm 101 is bowed to a somewhatgreater extent than its position in FIG. 5 whereby its spring actioncontinues to preserve the integrity of the seal assembly formed byelements 120, 121 and 123.

After the specimen chamber assembly has been properly coupled to thedrive assembly, as shown in FIGS. l and 6, motor 21 is started toproduce the high speed rotation of rotor shaft 118 whereby microblade126 macerates or homogenizes the materials in cup 92.

After the requisite macerating or homogenizing action has taken place,motor 21 is stopped, thereby stopping the rotation of rotor shaft 118and the specimen cup assembly may be removed from the drive assembly bylifting locking clamp 81 (FIGS. l, 5), thereby releasing detent springs76 so that when cup 92 is pulled downwardly, detents 77 move outwardlyfrom the recess 133 to release the specimen cup assembly. Simultaneouslywith the uncoupling of the specimen chamber assembly, when the lower endof high speed rotor 51 releases its pressure from the upper surface ofshoulder 119, core 102 acts resiliently to move seal face 123 upwardlyto its original position, as shown in FIG. 5, whereby seal washer 121 aswell as shoulder 119 are also moved upwardly until the latter abutsflange 114.

Thus, while the specimen cup assembly is being removed from the driveassembly, seal diaphragm 101 is operative to maintain the seal for thespecimen chamber as comprised by elements 120, 121 and 123, andautomatically moves said elements into their respective positions asshown in FIG. 5. Accordingly, by means of the structural arrangement ofthe parts herein, the specimen cup assembly can be uncoupled from thedrive assembly and carried in a sealed condition to another location forunloading its contents, Conversely, when Various specimens are insertedinto specimen cup 92 and sealed in one location of a laboratory, it canthen be transported to another location in the sealed condition andcoupled to the drive mechanism while maintaining the sealed condition.Accordingly, not only is contamination of the contents prevented, butalso deleterious consequences to laboratory personnel as a result ofpossible toxic or infectious materials in the specimen chamber areavoided. The preservation of the seal of the specimen cup be-l fore,during and after the homogenizing or macerating process facilitatesresearch in various biological, viral, bacteriological and pathologicalsubstances which would otherwise be difficult, if not impossible, toarrange. Furthermore, by utilizing such materials as stainless steel andinert plastic materials for the various components of the specimenchamber assembly, the assembly can readily be autoclaved or sterilizedeither in the assembled or disassembled condition.

Although spindle 51 is arranged to produce the action of separatingshoulder 119 from ange 114, to free rotor shaft 118 for rotation, it ispossible to arrange for the location of pin 128 lto be altered to aposition where its ends abut the inner end walls of slots 129 wherebythe respective locations of said pin and said walls would produce thedownward motion of shoulder 119.

In some embodiments of the invention it may be desirable to view theaction taking place within the specimen chamber. Accordingly, cup 92 maybe replaced by a stainless steel specimen cup 141 (FIG. l0) which has aplurality of spaced apart vertical elongated apertures 142. Fittingsnugly within cup 141 is a transparent or translucent inner cup 143 madeof a suitable plastic material within which the specimen is positionedfor maceration or homogenization. Thus, the extent of the maceratingaction can be viewed continuously and the operator can thereby controlthe timing and extent of the homogenizing process.

It is claimed:

1. Homogenizing apparatus having a body, a drive spindle rotatablymounted in said body, and a separate assembly of a specimen chamber androtor shaft releasably connectible to said body and said drive spindle,respectively, said assembly comprising a cup, a resilient diaphragmenclosing the interior of said cup and surrounding said rotor shaft, anaperture in said diaphragm through which said rotor shaft rotatablyextends, a cover on said cup enclosing said diaphragm, a seal betweensaid diaphragm and said shaft, said rotor shaft being movablelongitudinally through said cover, said shaft taking one positionrelative to said cover when coupled to said drive spindle and anotherposition relative to said cover when uncoupled from said drive spindle,said diaphragm maintaining the integrity of said seal in both positionsof said rotor shaft and when said assembly including said shaft isuncoupled from said body.

2. Homogenizing apparatus according to claim 1, and further comprisingmeans on said body for releasably connecting said assembly to said body,and means on said spindle and on said rotor shaft releasably couplingone another for rotation of the latter by the former, the dimensions ofthe components of the apparatus being such that when said assembly isconnected to said body said rotor shaft is moved from its first positionto its second position.

3. Homogenizing apparatus according to claim 1, and further comprisingan annular peripheral recess in said assembly, a pair of spring elementson said body, a portion of each of said spring elements adapted to matewith said recess, and a lock element pivotably mounted on said body andmovable into one position for causing said spring elements to retainsaid assembly in position against said body, said lock element beingmovable into a second position where said spring elements yieldablypermit said assembly to be removed `from said body.

4. Homogenizing apparatus according to claim 1, and further comprisingresilient means on said body for yieldably grasping said assembly andlocking means pivotably mounted on said body and movable into oneposition for causing said resilient means firmly to secure said assemblyin position relative to said body, said locking means being movable intoa second position where said resilient means yieldably permit saidassembly to be removed from `said body.

5. Apparatus according to claim l, and further comprising a longitudinalrecess in the end of said spindle,

said recess accommodating an end of said rotor shaft, at least oneperipheral slot in said spindle, a pin in said shaft accommodated bysaid slot whereby the rot-ation of said spindle causes the rotation ofsaid shaft.

6. Apparatus according to claim 1, and further comprising a longitudinalrecess in the end of said spindle accommodating an end of said rotorshaft, at least one peripheral slot in said spindle, a pin in said shaftaccommodated by said slot whereby the rotation of said spindle causesthe rotation of said shaft, the end of said spindle being 4beveledtoward the end of said slot whereby said pin is caused to move towardand become aligned with said slot when said shaft is coupled to saidspindle.

7. Apparatus according to claim 1 wherein said diaphragm comprises acircular at spring element consisting of a plurality of concentric ringsand integral bridges joining adjacent rings to each other, the centerportion of said spring being movable laterally relative to the plane ofsaid spring element.

8. Apparatus according to claim 1 wherein said diaphragm comprises acircular at spring element, the center portion of said element beingresiliently movable laterally relative to the plane thereof, a flexibleplastic coat ing bonded on and around said spring element, the peripheryof said coating forming an annular resilient ring, said ring forming aseal between said cup and said cover.

9. Apparatus according to claim 1, and further comprising an aperture onsaid cover through which said rotor rotatably extends, a shoulder onsaid shaft which is yieldably urged by said diaphragm against saidaperture, a central aperture yin said diaphragm through which said shaftrotatably extends, and a seal washer surrounding said shaft andcontinually urged by said diaphragm against a portion of said shaft tomaintain a seal between said shaft and said diaphragm.

10. Homogenizing apparatus having a body, a drive spindle rotatablymounted in said body and a separate assembly of a rotor shaft andspecimen chamber releasably connectible to said body and drive spindle,said assembly comprising a cup, a top cap threadably secured to saidcup, a central aperture in said cap, a resilient diaphragm mountedbetween said cup and said cap, a central aperture in said diaphragmaxially aligned with the cap aperture, an elongated rotor shaftextending through both said apertures, an annular shoulder on saidshaft, an annular ring positioned between said diaphragm and one side ofsaid shoulder and closing off said diaphragm aperture, said diaphragmnormally causing said shoulder to be urged against said cap to close olfthe cap aperture, means on said drive spindle and on said rotor shaftc0- operating with each other whereby the rotation of said spindlecauses the rotation of said shaft, means for releasably securing saidassembly to said body and cauS- Iing said rotor shaft to be coupled tosaid drive spindle, the dimensions of said spindle, shaft and securingmeans being selected to cause said shoulder on said shaft to be slightlydepressed from the cap aperture when said assembly is connected to saidbody, said ring continuing to maintain a seal over the diaphragmaperture whereby the interior of said cup is in a closed condition whensaid assembly is connected to and disconnected from said body.

11. Homogenizing apparatus comprising a drive means, a specimen cup, arotor shaft, part of said rotor shaft extending into the interior ofsaid cup and part of said shaft extending externally of said cup, theexterior portion of said rotor being releasably connectible to saiddrive means, and a resilient diaphragm connecting the intermediateportion of said shaft to said cup, said diaphragrn forming an enclosedspecimen chamber Within said cup and maintaining a seal between theexterior and the interior of said chamber when said rotor is connectedto and disconnected from said drive means and when said rotor rotates.

12. Homogenizing apparatus according to claim 11 wherein said diaphragmcontains a flat sheet metal element consisting of a plurality ofconcentric rings and integral bridges joining adjacent rings to eachother, said shaft extending through the center of said sheet metalelement.

13. Homogenizing apparatus according to claim 1l wherein said diaphragmcontains a at sheet metal element consisting of a plurality ofconcentric rings and integral bridges joining adjacent rings to eachother, said shaft extending through the center of said spring, andfurther comprising a seal washer positioned between said shaft and saidcentral portion of said diaphragm, the spring action of said diaphragmcausing said washer to maintain a seal between said diaphragm and saidrotor shaft.

14. Homogenizing apparatus comprising a specimen cup, a removable cap onsaid cup, a rotor shaft, an aperture in said cap through which saidrotor shaft extends and within which it freely rotates, a resilientdiaphragm positioned across the interior of said cup and defining aspecimen chamber within said cup, said diaphragm being retained inposition by said cap, the periphery of said diaphragm forming a sealbetween said cap and said cup, a central aperture in said diaphragmthrough which said rotor shaft rotatably extends, and a seal washerpositioned between said diaphragm and said rotor shaft, said diaphragmresiliently urging said seal washer against said shaft to maintain aseal for said specimen chamber while said shaft rotates and while it isat rest.

15. Homogenizing apparatus according to claim 14 wherein said shaft ismovable longitudinally within said cup, and further comprising anannular shoulder on said shaft, said diaphragm normally urging saidshoulder against said cap, said diaphragm maintaining said seal betweensaid washer and said rotor shaft during all positions of the latter.

16. Hornogenizing apparatus according to claim 14 wherein said diaphragmcontains a flat sheet metal element consisting of a plurality ofconcentric rings and integral bridges joining adjacent rings to eachother, said bridges permitting the center portion of said diaphragm tomove resiliently in a direction perpendicular to the normal planethereof.

17. Homogenizing apparatus according to claim 14 wherein said diaphragmcomprises a flat sheet metal element, and a exible plastic overlay inwhich said element is embedded, the periphery of said overlay beingformed in a circular H-shaped ring, said ring forming the seal betweensaid cap and said cup.

1S. Homogenizing apparatus according to claim 14 wherein said diaphragmcomprises a liat sheet metal element, and a flexible plastic overlay, apair of upwardly extending spaced apart concentric integral extensionsat the perimeter of said overlay, a pair of downwardly extending spacedapart concentric integral extensions at said perimeter, both of saidpairs of extensions forming the seal between said cap and said cup.

19. Homogenizing apparatus according to claim 14 wherein said diaphragmcomprises a flat sheet metal element, and a flexible plastic overlay inwhich said element is embedded, the periphery of said overlay formingthe seal between said cap and said cup.

20. Homogenizing apparatus according to claim 14 wherein said diaphragmcomprises a flat sheet metal element, and a flexible plastic overlay inwhich said element is embedded, the periphery of said overlay formingthe seal between said cap and said cup, and a plurality of integralteeth on the periphery of said metal element, said teeth being bentalternately in opposite perpendicular directions relative to the planeof said element and being embedded in said overlay.

21. Homogenizing apparatus according to claim 14 wherein said diaphragmincludes a flat sheet rnetal element consisting of three spaced apartconcentric rings, 50

each pair of adjacent rings being joined by diagonally opposed integralbridges, the bridges between one pair of adjacent rings being arrayed ina line perpendicular to the array of the other pair of bridges, thecentral ring being movable resiliently in a direction perpendicular tothe normal plane of said diaphragm.

22. Homogenizing apparatus according to claim 14 wherein said diaphragmcomprises a iiat sheet metal element consisting of three spaced apartconcentric rings, each pair of adjacent rings being joined by diagonallyopposed integral bridges, the bridges between one pair of adjacent ringsbeing arrayed in a line perpendicular to the array of the other pair ofbridges, the central ring being movable resiliently in a directionperpendicular to the normal plane of said diaphragm, and a exibleplastic overlay in which said metal element is embedded, the peripheryof said overlay being formed in a circular H- shaped ring, said ringforming the seal between said cap and said cup.

23. lelomogenizing apparatus comprising a body, a drive spindlerotatably mounted in said body, and a separate assembly of a specimencup and rotor shaft releasably connectible to said body and said drivespindle, respectively, a removable cap on said cup, an aperture in saidcap through which said rotor shaft extends and freely rotates, aresilient diaphragm positioned across the interior of said cup anddelining a specimen chamber therein, said diaphragm being retained inposition by said cap, a central aperture in said diaphragm through whichsaid rotor shaft rotatably extends, an annular tlange on said rotorshaft, said rotor shaft being movable longitudinally Within said cup, aseal washer positioned between said diaphragm and said flange, saiddiaphragm resilientiy urging said seal washer normally against saidflange to cause the latter to bear against said cap at said cap apertureand maintaining a seal between said shaft and said diaphragm forisolating said chamber from the atmosphere, means for removablyconnecting said assembly to said body, means removably coupling saidrotor shaft to said drive spindle, said drive spindle bearing againstsaid liange through said cap aperture when said rotor shaft is coupledto said drive spindle, the length of said drive spindle being determinedto cause said rotor shaft to move inwardly into the specimen chamberagainst the action of said diaphragm when said coupling takes place,said diaphragm continuing to maintain the seal between said seal washerand said iiange whereby the interior of said specimen chamber continuesto be isolated from the atmosphere.

References Cited in the file of this patent UNITED STATES PATENTS2,594,399 Cornell Apr. 29, 1952 2,766,022 Bender Oct. 9, 1956 2,973,187Wehmer Feb. 28, 1961

1. HOMOGENIZING APPARATUS HAVING A BODY, A DRIVE SPINDLE ROTATABLYMOUNTED IN SAID BODY, AND A SEPARATE ASSEMBLY OF A SPECIMEN CHAMBER ANDROTOR SHAFT RELEASABLY CONNECTIBLE TO SAID BODY AND SAID DRIVE SPINDLE,RESPECTIVELY, SAID ASSEMBLY COMPRISING A CUP, A RESILIENT DIAPHRAGMENCLOSING THE INTERIOR OF SAID CUP AND SURROUNDING SAID ROTOR SHAFT, ANAPERTURE IN SAID DIAPHRAGM THROUGH WHICH SAID ROTOR SHAFT ROTATABLYEXTENDS, A COVER ON SAID CUP ENCLOSING SAID DIAPHRAGM, A SEAL BETWEENSAID DIAPHRAGM AND SAID SHAFT, SAID ROTOR SHAFT BEING MOVABLELONGITUDINALLY THROUGH SAID COVER, SAID SHAFT TAKING ONE POSITIONRELATIVE TO SAID COVER WHEN COUPLED TO SAID DRIVE SPINDLE AND ANOTHERPOSITION RELATIVE TO SAID COVER WHEN UNCOUPLED FROM SAID DRIVE SPINDLE,SAID DIAPHRAGM MAINTAINING THE INTEGRITY OF SAID SEAL IN BOTH POSITIONSOF SAID ROTOR SHAFT AND WHEN SAID ASSEMBLY INCLUDING SAID SHAFT ISUNCOUPLED FROM SAID BODY.